Mapping localised freshwater anomalies in the brackish paleo-lake sediments of the Machile–Zambezi Basin with transient electromagnetic sounding, geoelectrical imaging and induced polarisation

A recent airborne TEM survey in the Machile-Zambezi Basin of south western Zambia revealed high electrical resistivity anomalies (around 100 Omega m) in a low electrical resistivity (below 13 Omega m) background. The near surface (0-40 m depth range) electrical resistivity distribution of these anomalies appeared to be coincident with superficial features related to surface water such as alluvial fans and flood plains. This paper describes the application of transient electromagnetic soundings (TEM) and continuous vertical electrical sounding (CVES) using geoelectrics and time domain induced polarisation to evaluate a freshwater lens across aflood plain on the northern bank of the Zambezi River at Kasaya in south western Zambia. Coincident TEM and CVES measurements were conducted across the Simalaha Plain from the edge of the Zambezi River up to 6.6 km inland. The resulting TEM, direct current and induced polarisation data sets were inverted using a new mutually and laterally constrained joint inversion scheme. The resulting inverse model sections depict a freshwater lens sitting on top of a regional saline aquifer. The fresh water lens is about 60 m thick at the boundary with the Zambezi River and gradually thins out and deteriorates in water quality further inland. It is postulated that the freshwater lens originated as a result of interaction between the Zambezi River and the salty aquifer in a setting in which evapotranspiration is the net climatic stress. Similar high electrical resistivity bodies were also associated with other surface water features located in the airborne surveyed area

Pomegranate juice, but not an extract, confers a lower glycemic response on a high–glycemic index food: randomized, crossover, controlled trials in healthy subjects

Background: Low–glycemic index diets have demonstrated health benefits associated with a reduced risk of developing type 2 diabetes. Objectives: We tested whether pomegranate polyphenols could lower the glycemic response of a high–glycemic index food when consumed together and the mechanism by which this might occur. Design: We compared the acute effect of a pomegranate juice and a polyphenol-rich extract from pomegranate (supplement) on the bread-derived postprandial blood glucose concentration in 2 randomized, crossover, controlled studies (double-blinded for the supplements), each on 16 healthy volunteers. An additional randomized, crossover, controlled study on 16 volunteers consuming constituent fruit acids in a pH-balanced solution (same pH as pomegranate) and bread was conducted to determine any contributions to postprandial responses caused by acidic beverages. Results: As primary outcome, the incremental area under the curve for bread-derived blood glucose (−33.1% ± 18.1%, P = 0.000005) and peak blood glucose (25.4% ± 19.3%, P = 0.0004) were attenuated by pomegranate juice, compared with a control solution containing the equivalent amount of sugars. In contrast, the pomegranate supplement, or a solution containing the malic and citric acid components of the juice, was ineffective. The pomegranate polyphenol punicalagin was a very effective inhibitor of human α-amylase in vitro, comparable to the drug acarbose. Neither the pomegranate extract nor the individual component polyphenols inhibited 14C-D-glucose transport across differentiated Caco-2/TC7 cell monolayers, but they inhibited uptake of 14C-glucose into Xenopus oocytes expressing the human glucose transporter type 2. Further, some of the predicted pomegranate gut microbiota metabolites modulated 14C-D-glucose and 14C-deoxy-D-glucose uptake into hepatic HepG2 cells. Conclusions: These data indicate that pomegranate polyphenols, when present in a beverage but not in a supplement, can reduce the postprandial glycemic response of bread, whereas microbial metabolites from pomegranate polyphenols exhibit the potential to further modulate sugar metabolism much later in the postprandial period. This trial was registered at clinicaltrials.gov as NCT02486978, NCT02624609, and NCT03242876

Biosorption of Pb (II) and Zn (II) from aqueous solution by Oceanobacillus profundus isolated from an abandoned mine

The present study investigated biosorption of Pb (II) and Zn (II) using a heavy metal tolerant bacterium Oceanobacillus profundus KBZ 3-2 isolated from a contaminated site. The effects of process parameters such as effect on bacterial growth, pH and initial lead ion concentration were studied. The results showed that the maximum removal percentage for Pb (II) was 97% at an initial concentration of 50 mg/L whereas maximum removal percentage for Zn (II) was at 54% at an initial concentration of 2 mg/L obtained at pH 6 and 30 °C. The isolated bacteria were found to sequester both Pb (II) and Zn (II) in the extracellular polymeric substance (EPS). The EPS facilitates ion exchange and metal chelation-complexation by virtue of the existence of ionizable functional groups such as carboxyl, sulfate, and phosphate present in the protein and polysaccharides. Therefore, the use of indigenous bacteria in the remediation of contaminated water is an eco-friendly way of solving anthropogenic contamination

Nutritional implications of olives and sugar: attenuation of post-prandial glucose spikes in healthy volunteers by inhibition of sucrose hydrolysis and glucose transport by oleuropein

Purpose: The secoiridoid oleuropein, as found in olives and olive leaves, modulates some biomarkers of diabetes risk in vivo. A possible mechanism may be to attenuate sugar digestion and absorption. Methods: We explored the potential of oleuropein, prepared from olive leaves in a water soluble form (OLE), to inhibit digestive enzymes (α-amylase, maltase, sucrase), and lower [¹⁴C(U)]-glucose uptake in Xenopus oocytes expressing human GLUT2 and [¹⁴C(U)]-glucose transport across differentiated Caco-2 cell monolayers. We conducted 7 separate crossover, controlled, randomised intervention studies on healthy volunteers (double-blinded and placebo-controlled for the OLE supplement) to assess the effect of OLE on post-prandial blood glucose after consumption of bread, glucose or sucrose. Results: OLE inhibited intestinal maltase, human sucrase, glucose transport across Caco-2 monolayers, and uptake of glucose by GLUT2 in Xenopus oocytes, but was a weak inhibitor of human α-amylase. OLE, in capsules, in solution or as naturally present in olives, did not affect post-prandial glucose derived from bread, while OLE in solution attenuated post-prandial blood glucose after consumption of 25 g sucrose, but had no effect when consumed with 50 g of sucrose or glucose. Conclusion: The combined inhibition of sucrase activity and of glucose transport observed in vitro was sufficient to modify digestion of low doses of sucrose in healthy volunteers. In comparison, the weak inhibition of α-amylase by OLE was not enough to modify blood sugar when consumed with a starch-rich food, suggesting that a threshold potency is required for inhibition of digestive enzymes in order to translate into in vivo effects

Biopsychosocial risk factors and knowledge of cervical cancer among young women: A case study from Kenya to inform HPV prevention in Sub-Saharan Africa

Background: Cervical cancer is the second most common female reproductive cancer after breast cancer with 84% of the cases in developing countries. A high uptake of human papilloma virus (HPV) vaccination and screening, and early diagnosis leads to a reduction of incidence and mortality rates. Yet uptake of screening is low in Sub-Saharan Africa and there is an increasing number of women presenting for treatment with advanced disease. Nine women in their twenties die from cervical cancer in Kenya every day. This paper presents the biopsychosocial risk factors that impact on cervical cancer knowledge among Kenyan women aged 15 to 24 years. The findings will highlight opportunities for early interventions to prevent the worrying prediction of an exponential increase by 50% of cervical cancer incidences in the younger age group by 2034. Methods: Data from the 2014 Kenya Demographic and Health Survey (KDHS) was analysed using complex sample logistic regression to assess biopsychosocial risk factors of knowledge of cervical cancer among young women aged 15 to 24 years (n = 5398). Findings: Close to one third of the participants were unaware of cervical cancer with no difference between participants aged 15–19 years (n = 2716) and those aged 20–24 years (n = 2691) (OR = 1; CI = 0.69–1.45). Social predisposing factors, such as lack of education; poverty; living further from a health facility; or never having taken a human immunodeficiency virus (HIV) test, were significantly associated with lack of awareness of cervical cancer (p<0.001). Young women who did not know where to obtain condoms had an OR of 2.12 (CI 1.72–2.61) for being unaware of cervical cancer. Psychological risk factors, such as low self-efficacy about seeking medical help, and an inability to refuse unsafe sex with husband or partner, perpetuated the low level of awareness about cervical cancer (p<0.001). Conclusions: A considerable proportion of young women in Kenya are unaware of cervical cancer which is associated with a variety of social and psychological factors. We argue that the high prevalence of cervical cancer and poor screening rates will continue to prevail among older women if issues that affect young women’s awareness of cervical cancer are not addressed. Given that the Kenyan youth are exposed to HPV due to early sexual encounters and a high prevalence of HIV, targeted interventions are urgently needed to increase the uptake of HPV vaccination and screening

Shepherding sub-Saharan Africa's wildlife through peak anthropogenic pressure toward a green anthropocene

Sub-Saharan Africa’s (SSA’s) iconic biodiversity is of immense potential global value but is jeopardized by increasing anthropogenic pressures. Elevated consumption in wealthier countries and the demands of international corporations manifest in significant resource extraction from SSA. Biodiversity in SSA also faces increasing domestic pressures, including rapidly growing human populations. The demographic transition to lower fertility rates is occurring later and slower in SSA than elsewhere, and the continent’s human population may quadruple by 2100. SSA’s biodiversity will therefore pass through a bottleneck of growing anthropogenic pressures, while also experiencing intensifying effects of climate change. SSA’s biodiversity could be severely diminished over the coming decades and numerous species pushed to extinction. However, the prospects for nature conservation in SSA should improve in the long term, and we predict that the region will eventually enter a Green Anthropocene. Here, we outline critical steps needed to shepherd SSA’s biodiversity into the Green Anthropocene epoch.http://www.annualreviews.orgam2023Mammal Research InstituteZoology and Entomolog

Acute metabolic actions of the major polyphenols in chamomile: an in vitro mechanistic study on their potential to attenuate postprandial hyperglycaemia

Transient hyperglycaemia is a risk factor for type 2 diabetes and endothelial dysfunction, especially in subjects with impaired glucose tolerance. Nutritional interventions and strategies for controlling postprandial overshoot of blood sugars are considered key in preventing progress to the disease state. We have identified apigenin-7-O-glucoside, apigenin, and (Z) and (E)-2-hydroxy-4-methoxycinnamic acid glucosides as the active (poly)phenols in Chamomile (Matricaria recutita) able to modulate carbohydrate digestion and absorption in vitro as assessed by inhibition of α-amylase and maltase activities. The latter two compounds previously mistakenly identified as ferulic acid hexosides were purified and characterised and studied for their contribution to the overall bioactivity of chamomile. Molecular docking studies revealed that apigenin and cinnamic acids present totally different poses in the active site of human α-amylase. In differentiated Caco-2/TC7 cell monolayers, apigenin-7-O-glucoside and apigenin strongly inhibited D-[U-14C]-glucose and D-[U-14C]-sucrose transport, and less effectively D-[U-14C]-fructose transport. Inhibition of D-[U-14C]- glucose transport by apigenin was stronger under Na+-depleted conditions, suggesting interaction with the GLUT2 transporter. Competitive binding studies with molecular probes indicate apigenin interacts primarily at the exofacial-binding site of GLUT2. Taken together, the individual components of Chamomile are promising agents for regulating carbohydrate digestion and sugar absorption at the site of the gastrointestinal tract

Track D Social Science, Human Rights and Political Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138414/1/jia218442.pd